SANTA CLARA, Calif. -- Greetings from the construction site known as San Francisco 49ers headquarters. The new stadium dwarfs the facility across the blocked-off street. I'll be watching practices and conducting interviews over the next couple days.Depth issues at receiver have pushed second-year 49ers receiver A.J. Jenkins into the training camp spotlight. The 49ers aren't the only team seeking 2013 contributions from skill-position players drafted in 2012.